---

Solution

Each letter is shifted forward by one place in the alphabet: $A \to B,\ P \to Q,\ L \to M,\ E \to F,\ S \to T.$ Applying the same to “ORANGE”: $O \to P,\ R \to S,\ A \to B,\ N \to O,\ G \to H,\ E \to F.$ So “ORANGE” $\to$ PSBODF.